When was the last time you thought about your home’s air ducts? If you’re like most homeowners, the answer is probably “not recently.” But your ductwork plays a big role in your home’s air quality and overall HVAC performance. Over time, dust, dirt, pet dander, and even mold can build up inside your ducts, which can affect your indoor air and your system’s efficiency. So, how often should you schedule a professional air duct cleaning?